Known in the art is a light guide device for phototherapy comprising an optical fiber light guide and a light cattering member in the form of a bare light guiding strand of the light guide the periphery of which is treated with hydrofluoric acid (Optics and Laser Technology. 1984, February. H. Fujii et al. "Light Scattering Properties of a Rough-Ended Optical Fiber", pp. 40, 41).
This device cannot be used for carrying out intracavitary laser treatment procedures because of high danger: the light scattering member is in the form of a brittle member which is very likely to be broken in the patient body.
Known in the art is a light guide device for phototherapy comprising an optical fiber light guide having a light guiding strand, light reflecting and protective envelopes and a light scattering member provided at the distal end of the optical fiber light guide (Laser in Surgery and Medicine, No. 6, 1986. M. Arnfield et al. "Cylindrical Irradiator Fiber Tip for Photodynamic Therapy. p. 151).
In this light guide device for phototherapy, the light scattering member is in the form of a sleeve having end faces of its walls cemented to a bare portion of a light guiding strand of the optical fiber light guide, a layer of epoxy resin being applied to the inner surface of the sleeve walls.
This device cannot ensure safety of a patient in carrying out intracavitary laser treatment procedures, i.e. it is dangerous and may cause injury.
This device is also complicated in the manufacture. Moreover, this device can only ensure one type of the indicatrix of light distribution of the radiation, i.e. it cannot ensure matching of the shape of indicatrix of light distribution of the radiation to the shape of a pathological focus so as to optimize the effect of the therapy factor.